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Beck Property,Tracy,CA November 1988 Site Investigation Analytical results for CAM Metals (EPA Method 6010) on both the reservoir and the background (school site) composite samples indicate low and relatively consistent metal concentrations. AEMC determines there exist no indication or evidence of metal contamination in the surface soils. Laboratory analysis for Semi-volatile Organics (EPA Method 8270) identified no contaminants in the two composite surface soil samples. Laboratory analysis for Organochlorine Pesticides (EPA Method 8080) in the two composite samples indicated the presence of contaminants in very low concentrations. The types and concentrations of the persistent organochlorines detected in the surface samples are very common and generally accepted in agricultural communities. AEMC believes these levels present no threat to the environment or human health and safety. Subsurface Soil Boring Samples (within reservoir) • AEMC was able to positively determine the depth to bottom of the oil reservoir at each of the borehole locations. Allowing for a one-foot margin of error in depth determination, AEMC documented the bottom depths ranging from 7.5 feet to 9.0 feet. Refer to the Soil Boring Logs presented in Appendix 2 for bottom depth documentation. Evidence of varying degrees of oil contaminated soil was detected on the reservoir bottom in each of the eight auger borings positioned within the reservoir. No evidence of oil contaminated soil was detected from the ground surface down to the 5-foot depth in any of the 8 auger borings. The Soil Boring Logs document AEMC field observations at each auger boring location. Field observations and laboratory analyses of boring samples clearly indicate a greater quantity of oil residue in the southern half of the reservoir. This confirms the assumptions AEMC and Beck derived from the field investigations conducted in September 1986 (refer to the Report of Preliminary Investigation - 13 October 1986). Following are calculations derived from the Total Recoverable Hydrocarbon (TRHC) analysis: rl�c-01(2) Page 14